Touch control detecting method and touch control detecting system

ABSTRACT

A touch control detecting method applied to an electronic apparatus comprising an image sensor. The touch control detecting method comprises: (a) capturing a plurality of sensing images via the image sensor; and (b) determining if an object performs a predetermined touch control operation to the electronic apparatus, according to a brightness variation tendency of the sensing images.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a touch control detecting method and atouch control detecting system, and particularly relates to a touchcontrol detecting method and a touch control detecting system which canapply a brightness variation tendency of an image to determine a touchcontrol operation.

2. Description of the Prior Art

Recently, a smart electronic apparatus such as a tablet computer becomesmore and more popular. Such kind of smart electronic apparatus alwaysapplies a capacitive touch control screen as a control interface.However, the capacitive touch control screen is hard to determine somecomplex operations such as continuous tap. Also, under somecircumstances, user's touch control operations are hard to be determinedby the capacitive touch control screen. For example, if a user wears aglove to perform a touch control operation to the capacitive touchcontrol screen, the capacitance value of the capacitive touch controlscreen does not change even if the user touches, since the glove is madefrom insulation materials. For such case, the capacitive touch controlscreen cannot determine user's touch control operations.

In order to provide a convenient control interface to a smart electronicapparatus, some manufacturers provide hardware buttons as the controlinterface of the smart electronic apparatus. FIG. 1 is a schematicdiagram illustrating that a hardware button is applied as a controlinterface in the prior art. As illustrated in FIG. 1, the electronicapparatus 100 comprises a hardware button 101. A user can set thehardware button as a common function button. Such kind of hardwarebutton can be a button fixed on the electronic apparatus 100, or aremovable button. However, each kind of buttons has some defects.

For example, if the hardware button 101 is a button fixed to theelectronic apparatus 100, the electronic apparatus 100 must provide aregion for the hardware button and accordingly has a bigger size. Suchbigger size does not meet the requirements for a modern electronicapparatus. If the hardware button 101 is a removable hardware button,the electronic apparatus 100 must have a plug corresponding to thehardware button, like an earphone plug. However, the plug may notperform the function it originally has while the hardware button is setin the plug. The user may lost the hardware button 101 while thehardware button 101 is not set to the plug.

SUMMARY OF THE INVENTION

Therefore, one objective of the present invention is to provide a touchcontrol detecting method which can apply sensing images to determine thetouch control operations.

Another objective of the present invention is to provide a touch controldetecting system which can apply sensing images to determine the touchcontrol operations.

One embodiment of the present invention disclose a touch controldetecting method applied to an electronic apparatus comprising an imagesensor. The touch control detecting method comprises: (a) capturing aplurality of sensing images via the image sensor; and (b) determining ifan object performs a predetermined touch control operation to theelectronic apparatus, according to a brightness variation tendency ofthe sensing images.

Another embodiment of the present invention discloses a touch controlsystem comprising: an image sensor, configured to capture a plurality ofsensing images; and a control unit, configured to determine if an objectperforms a predetermined touch control operation to a control interface,according to a brightness variation tendency of the sensing images.

In view of above-mentioned embodiments, the sensing images can beapplied to determine the touch control operation. Accordingly, theissues due to the capacitive touch control screen or the hard warebutton illustrated in prior art can be avoided.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating that a hardware button isapplied as a control interface in the prior art.

FIG. 2 is a schematic diagram, which illustrates applying a brightnessvariation direction presented by a plurality of sensing images todetermine which direction button is taped, according to one embodimentof the present invention.

FIG. 3 is a schematic diagram illustrating the brightness variation fora plurality of sensing images while a finger performing a tap operation.

FIG. 4 is a schematic diagram illustrating how to determine if acontinuous tap operation occurs according to the brightness presented bya plurality of sensing images.

FIG. 5 is a schematic diagram illustrating the brightness variationtendency for a plurality of sensing images while a finger performing along press operation.

FIG. 6 and FIG. 7 are schematic diagrams illustrating the touchoperations that may be wrongly determined as a long press operation.

FIG. 8 is a schematic diagram illustrating a state machine, whichdetermines if a predetermined touch control operation is performed basedon a brightness variation tendency of sensing images, according todifferent embodiments of the present invention.

FIG. 9 is a block diagram illustrating a touch control detecting systemaccording to one embodiment of the present invention.

DETAILED DESCRIPTION

Various embodiments are provided to explain the concept of the presentinvention. Please note, the system, apparatus or module in followingembodiments can be implemented by hardware (ex. circuit), or thecombination of hardware and software (ex. a processing unit executing atleast one program). Additionally, a finger is applied as an example forthe object in the following embodiments. However, please note otherobjects besides the finger, such as a touch control pen, can be appliedfor the present invention. Furthermore, in following embodiments, atouch control screen is applied for explaining, but the presentinvention can be applied to other touch control interfaces (ex. anoptical touch control pad).

In following embodiments, an image sensor is applied for capturing aplurality of sensing images, and then the brightness variation tendencyof the sensing images is applied to determine if the finger performs apredetermined touch control operation to an electronic apparatus. In oneembodiment, the image sensor is always on, such that all touch controloperations can be detected, but it does not mean to limit. In oneembodiment, the image sensor firstly captures sensing images via a lowresolution, and switches to a higher resolution to capture the sensingimage if brightness varies, which means a finger is moving closer.

FIG. 2 is a schematic diagram, which illustrates applying a brightnessvariation direction presented by a plurality of sensing images todetermine which direction button is taped, according to one embodimentof the present invention. In this embodiment, a plurality of directionkeys, such as an up key U, a down key D, a left key L and a right key Rare displayed on the electronic apparatus. The sensing images present ina particular manner if the user wants to tap or to long-press any one ofthe direction keys. For example, the finger always presents a movingoperation which is from right to left if the user taps or long-pressesthe left key L. Accordingly, as illustrated in FIG. 2, the lowbrightness region DR_1 firstly appears in a right part, and then movesto the left. In another example, if the user taps the up key U, thefinger always moves from down to up. Accordingly, as illustrated in FIG.2, the low brightness region DR_2 firstly appears in a down part, andthen moves to the up. In view of above-mentioned descriptions, theembodiment illustrated in FIG. 2 determines which one of the directionkeys does the object tap according to the brightness variation directionpresented by the sensing images.

The steps for determining if a continuous tap operation is performed areillustrated in great detail in following descriptions. In followingembodiments, an image sensor of the electronic apparatus is applied tocapture sensing images, which are applied for determining touch controloperations. FIG. 3 is a schematic diagram illustrating the brightnessvariation for a plurality of sensing images while a finger performing atap operation. As illustrated in FIG. 3, the finger gradually movescloser to the touch control screen if a tap operation is performed, thussensing images Img (only one sensing image is marked by a symbol) have atendency of becoming from bright to dark, for example, the sensingimages Img at time points t1-t9. Additionally, the finger blocks thelight while touching the touch control screen, thus the sensing imagesImg are dark images, for example, the sensing images Img at time pointst10-t11. Also, if the finger is leaving the touch control screen, thesensing images Img have a tendency of becoming from dark to bright, forexample, the sensing images Img at time points t12-t14. In view of thecontents of FIG. 3, the tap operation can be determined according to ifbrightness of the sensing images is higher than a high brightnessthreshold value or lower than a low threshold value.

FIG. 4 is a schematic diagram illustrating how to determine if acontinuous tap operation occurs according to the brightness presented bya plurality of sensing images. In view of the content illustrated inFIG. 3, if brightness of the sensing images changes from high to belower or equals to the low brightness threshold value Th_low, and thenbecomes to be higher or equal to the high brightness threshold valueTh_high, it can be determined that the finger performs a tap operation.Therefore, in the embodiment of FIG. 4, the finger performs four timesof taps in a predetermined time interval, thus is regarded as acontinuous tap operation having four taps. In view of above-mentioneddescriptions, the embodiment in FIG. 4 can be regarded as: it isdetermined that a continuous tap operation is performed if times forthat brightness increases to a high brightness threshold value anddecreases to a low brightness threshold value is higher or equal to acontinuous tap threshold value in a predetermined time period.

In one embodiment, the brightness of sensing images is converged to aconvergence value CV. Therefore, as illustrated in FIG. 4, if no objectis closer to the image sensor, the average brightness of sensing imagesis adjusted to converge at a convergence value CV. By this way, the tapor continuous tap operation can be determined more easily.

FIG. 5-FIG. 7 are schematic diagrams illustrating how to determine if along press operation is performed based on the brightness variationtendency presented by sensing images, according to different embodimentsof the present invention. A long press operation for the fingercomprises: putting down the finger, directly or non-directly pressingthe image sensor, and the finger leaves. Based on the description ofFIG. 3, it can be understood that the sensing image is a dark image ifthe finger touches the touch control screen. Therefore, if the fingerperforms a long press operation, the number for dark sensing imagesincreases. For example, the number for dark sensing images becomes fromtwo to four, six or more if the finger performs a long press operation.

Please refer to FIG. 5, which is a schematic diagram illustrating thebrightness variation tendency for a plurality of sensing images while afinger performing a long press operation. As illustrated in FIG. 5,after brightness of the sensing image decreases to be lower or equal tothe low brightness threshold value Th_low (i.e. the finger press), thebrightness of following sensing images is adjusted to the convergencevalue CV. Please note, if the brightness of the sensing image is notadjusted, the sensing image is a dark sensing image since the fingerblocks the image sensor. The brightness of following sensing imagesmaintains at the convergence value CV for a predetermined time interval(ex. 1 second, but can be other values), and then the brightness offollowing sensing images increases to the high brightness thresholdvalue Th_high (i.e. the finger leaves). Therefore, the embodiment inFIG. 5 can be summarized as follows: it is determined that the longpress operation is performed if the brightness variation tendency is:the brightness decreases to be lower or equal to the low brightnessthreshold value Th_low and then converges to a convergence value CV, andthen increases to be equal to or higher than the high brightnessthreshold value Th_high, and a time interval that the brightness equalsthe convergence value CV is satisfied with a predetermined time interval(i.e. higher or equal).

FIG. 6 and FIG. 7 are schematic diagrams illustrating the touchoperations that may be wrongly determined as a long press operation. Asillustrated in FIG. 6, the brightness of a plurality of sensing imagesdoes not converge to the convergence value CV after decreases to belower or equal to the low brightness threshold value Th_low. On theopposite, the brightness of a plurality of sensing images directlyincreases to be higher or equal to a high brightness threshold valueTh_high. Therefore, the touch control operation may be a tap rather thana long press. Besides, in the example of FIG. 7, the brightness of aplurality of sensing images converges to the convergence value CV ratherthan increases to be higher or equal to a high brightness thresholdvalue Th_high after decreases to be lower or equal to the low brightnessthreshold value Th_low. Such situation may be caused by moving theelectronic apparatus to a darker place or covering the electronicapparatus via other stuffs, rather than caused by a long press.

FIG. 8 is a schematic diagram illustrating a state machine, whichdetermines if a predetermined touch control operation is performed basedon a brightness variation tendency of sensing images, according todifferent embodiments of the present invention. As illustrated in FIG.8, the electronic apparatus may operate in four states: a non touchcontrol state S_1 (ex. the electronic apparatus is put on the table orin the bag), a finger press state S_2 (ex. states t10, t11 in FIG. 3), afinger raise state S_3 (ex. states t12-t14 in FIG. 3) and a touchcontrol operation confirming state S_4. The electronic apparatus is inthe non touch control state S_1 if the electronic apparatus is notoperated by a user. Also, the state changes to the finger press stateS_2 if the brightness Br of the sensing images sensed by the imagesensor of the electronic apparatus is lower or equal to the lowbrightness threshold value Th_low. In the finger press state S_2, if thebrightness changes to be higher or equal to the high brightnessthreshold value Th_high, the state enters the finger raise state S_3. Onthe opposite, the state goes back to the non touch control state S_1. Inthe finger raise state S_3, the state enters the touch control operationconfirming state S_4 if the brightness Br of the sensing imagesconverges to the convergence value CV. Besides, if the brightness BRgradually decreases to be lower or equal to the low brightness thresholdvalue Th_low, the state goes back to the finger press state S_2.

In the touch control operation confirming state S_4, the touch controloperation can be determined based on above-mentioned rules, which means:the brightness Br decreases to be lower or equal to the low brightnessthreshold value Th_low, and then increases to be higher or equal to thehigh brightness threshold value Th_high. Also, the touch controloperation can be determined based on other factors. For example, if oncethe following operation illustrated in FIG. 6 occurs: the brightness Brdecreases to be lower or equal to the low brightness threshold valueTh_low, and then increases to be higher or equal to the high brightnessthreshold value Th_high, the touch control operation can be determinedas a tap operation. If times for the brightness Br decreases to be loweror equal to the low brightness threshold value Th_low, and thenincreases to the high brightness threshold value Th_high is higher thana continuous tap threshold value (as illustrated in FIG. 4), the touchcontrol operation is determined as a continuous tap operation.Furthermore, the touch control operation is determined as a long pressoperation if the brightness BR decreases to be lower or equal to the lowbrightness threshold value Th_low and then converges to a convergencevalue CV for a predetermined time interval (i.e. a converging intervalexists), and then increases to be equal to or higher than the highbrightness threshold value Th_high, as illustrated in FIG. 5.

FIG. 9 is a block diagram illustrating a touch control detecting systemaccording to one embodiment of the present invention. As illustrated inFIG. 9, the touch control detecting system 900 comprises: an imagesensor 901, a convergence module 903, a control unit 905, a counter 907,a long press module 909, a continuous tap module 911 and a direction keymodule 913. The image sensor 901 is configured to capture a plurality ofsensing images. The convergence module 903 is configured to adjust thebrightness for the sensing images captured by the image sensor 901 tothe above-mentioned convergence value CV. Many methods can be applied toadjust the brightness of sensing images, for example, adjusting the gainvalue of the images signals of sensing images. The control unit 905 isconfigured to control each device. The counter 907 is configured tocompute times for that brightness of sensing images is higher or equalto a high brightness threshold value Th_high and is lower than or equalto a low brightness threshold value Th_low according to the thresholdvalue Th, which comprises the high brightness threshold value Th_highand the low brightness threshold value Th_low. The long press module909, the continuous tap module 911 and the direction key module 913 arerespectively configured to determine the above-mentioned long pressoperation, continuous tap operation and direction key tap operation.

It will be appreciated that the convergence module 903, the long pressmodule 909, the continuous tap module 911 and the direction key module913 can be implemented by software, and can be integrated to the controlunit 905. Additionally, the counter 907 can be integrated to the controlunit 905. Therefore, the touch control detecting system can besummarized as: A touch control system, comprising: an image sensor (ex.901 in FIG. 9), configured to capture a plurality of sensing images; anda control unit (ex. 905 in FIG. 9), configured to determine if an objectperforms a predetermined touch control operation to a control interface,according to a brightness variation tendency of the sensing images.

In view of above-mentioned embodiments, the sensing images can beapplied to determine the touch control operation. Accordingly, theissues due to the capacitive touch control screen or the hard warebutton illustrated in prior art can be avoided. Besides, since thepresent invention determines touch control operation by opticalmechanism, the body of the electronic apparatus does not need a hole fora conventional key or a conventional button if the electronic apparatusapplies the mechanism provided by the present invention to determine atap. Accordingly, the disturbance due to the dust or moisture can beavoided.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A touch control detecting method, applied to anelectronic apparatus comprising an image sensor, comprising: (a)capturing a plurality of sensing images via the image sensor; and (b)determining if an object performs a predetermined touch controloperation to the electronic apparatus, according to a brightnessvariation tendency of the sensing images.
 2. The touch control detectingmethod of claim 1, wherein the predetermined touch control operation isa direction key tap operation.
 3. The touch control detecting method ofclaim 2, wherein the step (b) determines which one of direction keysdoes the object tap according to a brightness variation directionpresented by the sensing images.
 4. The touch control detecting methodof claim 1, wherein the predetermined touch control operation is acontinuous tap operation.
 5. The touch control detecting method of claim4, wherein the step (b) determines the object performs the continuoustap operation if the brightness variation tendency is: times for thatbrightness increases to a high brightness threshold value and decreasesto a low brightness threshold value is higher or equal to a continuoustap threshold value in a predetermined time period.
 6. The touch controldetecting method of claim 1, wherein the predetermined touch controloperation is a long press operation.
 7. The touch control detectingmethod of claim 6, wherein the step (b) determines the predeterminedtouch control operation is the long press operation if the brightnessvariation tendency is: the brightness decreases to be lower or equal tothe low brightness threshold value and then converges to a convergencevalue, and then increases to be equal to or higher than the highbrightness threshold value, and a time interval that the brightnessequals the convergence value is higher or equal to a predetermined timeinterval.
 8. The touch control detecting method of claim 1, wherein thetouch control detecting method is applied to a touch control screen. 9.The touch control detecting method of claim 1, wherein the touch controldetecting method is applied to an optical touch control pad.
 10. A touchcontrol system, comprising: an image sensor, configured to capture aplurality of sensing images; and a control unit, configured to determineif an object performs a predetermined touch control operation to acontrol interface, according to a brightness variation tendency of thesensing images.
 11. The touch control system of claim 10, wherein thepredetermined touch control operation is a direction key tap operation.12. The touch control system of claim 11, wherein the control unitdetermines which one of direction keys does the object tap according toa brightness variation direction presented by the sensing images. 13.The touch control system of claim 10, wherein the predetermined touchcontrol operation is a continuous tap operation.
 14. The touch controlsystem of claim 13, wherein the control unit determines the objectperforms the continuous tap operation to the control interface if thebrightness variation tendency is: times for that brightness increases toa high brightness threshold value and decreases to a low brightnessthreshold value is higher or equal to a continuous tap threshold valuein a predetermined time period.
 15. The touch control system of claim10, wherein the predetermined touch control operation is a long pressoperation.
 16. The touch control system of claim 15, wherein the controlunit determines the object performs the long press operation to thecontrol interface if the brightness variation tendency is: thebrightness decreases to be lower or equal to the low brightnessthreshold value and then converges to a convergence value, and thenincreases to be equal to or higher than the high brightness thresholdvalue, and a time interval that the brightness equals the convergencevalue is higher or equal to a predetermined time interval.
 17. The touchcontrol system of claim 10, wherein the control interface is a touchcontrol screen.
 18. The touch control system of claim 10, wherein thecontrol interface is an optical touch control pad.